The invention generally relates to systems and methods which may be applied to communications and other types of electronics systems. In particular the invention relates to systems and methods which provide for filtering of low frequency emissions onto the prime power line for the communications equipment.
Various conventional electronic systems with significant load modulation, such as RF power amplifier applications, may result in significant low-frequency current emissions that are conducted back out on the power line. For example, modulation waveforms such as AM voice, ASK AM, Have. Quick IIA, and the like, all may exhibit such emissions. Electromagnetic Interference/Electromagnetic Compatibility (EMI/EMC) standards such as MIL-STD-461 CE101, limit the conducted emissions that an equipment may generate at the power input interface. Meeting these requirements for low frequency emissions, such as for AM voice, requires filters (including large capacitors and inductors) with low cutoff frequencies and correspondingly large volume and weight, both of which may be particularly undesirable in both airborne and mobile applications.
Accordingly, there is a need for a system and method of reducing power line emissions in RF applications which provide both weight and volume savings over conventional solutions. There is also a need for a system and method which reduces power line emissions in RF applications by utilization of one or more capacitors which are substantially smaller than those used in conventional solutions.
The techniques herein below extend to those embodiments which fall within the scope of the appended claims, regardless of whether they accomplish one or more of the above-mentioned needs.